John isaac thornycboft



(No Model.) 2 Sheets-Sheet 1.

J. I. THORNYGROFT.

, WATER TUBE BOILER. No. 555,543. Patented Mar. 3, 1896.

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J. I. THORNYCROPT. WATER TUBE BOILER.

No. 555,543. Patented Mar. 3, 1896.

PI! I I "III 3. nullllll NrrED STATES JoHN ISAAC THORNYCROFT, or LONDON,ENGLAND.

WATER-TUBE BOILER.

SPECIFICATION forming part of Letters Patent No. 555,543, dated March 3,1896.

Application filed December 13,1894. Serial No. 531,669. (No model.)Patented in England October 4, 1894, No. 18,838; in France December 22,1894, No. 243,872; in Italy December 31, 1894, No. 231; in SwitzerlandJanuary 3, 1895, No. 9,751; inBelgium July 16,1895,No.116,563; inAustria October 22, 1895, No. 8,973, and in Denmark December 2,1895,

To all whom it may concern:

Be it known that I, JOHN ISAAC THORNY- CROFT, a subject of the Queen ofGreat Britain and Ireland, residing at Chiswick, London, in the countyof Middlesex, England, have invented Improvements in "Water-TubeBoilers, (for which Letters Patent have been granted as follows: inGreat Britain, dated October 4, 1894, No. 18,838; in France, datedDecember 22, 1894, No. 243,872; in Austria, dated October 22, 1895, No.3,973; in Italy, dated December 31, 1894, N0. 231; in Denmark, datedDecember 2, 1895, No. 310; in Switzerland, dated January 3, 1895, No.9,751, and in Belgium, dated July 16, 1895, No. 116,563.) of which thefollowing is a specification.

This invention has reference to an improved construction and arrangementof Water-tube boiler, specially designed for use in navigable vessels ofsmall size, such as launches and pinnaces, as I will now proceed toexplain by the aid of the accompanying illustrative drawings, in whichFigure 1 is a longitudinal vertical section, and Fig. 2 a cross-section,showing my improved boiler. Figs. 3 and 4 are, respectively, a sideelevation and horizontal section showin g an improved construction ofbaffle for use in such boiler. Fig. 5 is a sectional detail view.

A steam-boiler according to this invention comprises an upperlongitudinal combined steam collector and separator 1 (hereinaftercalled a steam-drum) and a lower longitudinal water-vessel 2, thesebeing arranged one above the other at one side of and within a casing 3so as to extend from front to back of the boiler. They are connected bya main longitudinal group of bent tubes 4 that serve to divide theinterior of the casing, practically in a diagonal manner, into twolongitudinal chambers 5 and 6, the lower of which viz., 5serves as afire-box, and in the upper of which-via, 6the steam-drum 1 is located.The downtake-tube 7 or tubes connecting the bottom of the steam-drumwith the water-vessel is orare or may be also arranged within the saidupper chamber, 6, as in the example shown, though it or they may,

if desired, be external to the boiler-casing IVhen arranged in the saidupper chamber, as shown, several of such tubes may be used. The tubes 4composing the main longitudinal group of tubes form one side and theroof of the fire-box 5, and are so bent and disposed in a manner nowwell understood in connection with water-tube boilers of the Thornycrofttype, and as shown in the drawings, that some of them form two closewalls 4 4 of a flue 4, within which the remaining tubes are arranged,this fiue communicating at its lower part with the fire-box throughopenings 4 between the lower ends of the tubes forming the inner wall 4of such box, and at its upper end, through similar openings 4 4 betweenthe upper ends of the tubes, forming the walls 4 4 ,with the uptake 8,either directly through the portion of the upper chamber, 6, that isabove the steam-drum 1 by passing through the openings 4*, or indirectlythrough the portion of the said chamber 6 that is below the said drum bypassing through the opening 4 or through both of these portions ofthesaid chamber by passing through both sets of openings 4 and 4simultaneously.

The openings 4 formed by the bending of the lower ends of the tubesconstituting the wall 4 are closed by refractory material, such asfire-clay, to prevent escape of flame and hot gases at these points. Theother side of the fire-box 5 is formed by bent tubes 9, arranged closetogether and in a row along their vertical portions and connected attheir upper and lower ends with the steam-drum 1 and water-vessel 2,respectively, their upper ends being so bent and disposed, as shown, asto extend over the upper ends of the bent tubes 4, and so as to leaveopenings 9 between them through which the hot gases and products ofcombustion, after passing through the opening 4 between the upper endsof the tubes 4 forming the wall 4, can pass direct to the uptake 8.

The upper ends of the tubes 4 and 9 are shown connected to the upperside of the steam-drum, as I consider this the most advantageousarrangement, but I do not limit myself to such an arrangement, as theymay be connected to any other desired part of the steam-drum, in whichcase the position of the said drum can also be changed if desired. Thetubes 9 may, at their lower ends, be advantageously bent inward, asshown, toward the water-vessel 2 to which they are connected, so as toform hollow grate-bars 9", through which water will circulate when theboiler is in action, the portions of the said tubes forming the saidgrate-bars being made of smaller diameter than the remaining portions inorder to form air-passages between them, as shown in Fig. 1. Thisconstruction of one side of a tire-box and fire-grate by a row of tubesmay advantageously be used in constructions of water-tube boilers otherthan that hereinbefore described. To obviate damage of the hollowgrate-bars by direct contact with the fuel and by the tools used toclean the fire, the said hollow grate-bars may be partially protected byremovable bars 9" of approximately T shape in cross-section and havingpreferably a convex upper surface, as shown in Fig. 5, these bars beingarranged at intervals so as not to materially interfere with thefurnace-draft.

10 is a blast-pipe extending through the upper chamber (3 andterminating at the base of the uptake 8:

11 is refractory material, such as fireclay, arranged at the sides andends of the firegrate to protect the adjacent portions of the tubes 4:and J and end walls of the casing 3 from direct contact with the fuel onthe grate.

To control the direction of the escaping hot gases and products ofcombustion, a ilap or damper suit-ably slotted to clear the blastpipe10, or two separate flaps or dampers 12 arranged a short distance apartfor a like purpose and carried by a spindle 13, may be arranged abovethe upper ends of the bent tubes 4 and 9, as shown, so that when turnedinto the-dotted position shown in Fig. 2 by an external handle 14 it orthey will permit the hot gases and products of combustion to passdirectly to the uptake through the openings 4 and 9, and when turnedinto the position shown in full lines in the same figure will cause thesaid hot gases and products of combustion to pass through the openings ito the lower side of the steam-drum and thence to the uptake 8.

To simplify and chcapen the construction of the steam-drum andwater-vessel, and to permit of access being readily gained to theirinteriors, the end covers of each of them are or may be secured in placeby one or more bolts passing lengthwise completely through thesteam-drum or water-vessel, as the case may be, and the end covers, andprovided on its or their outer ends with holding-up nuts, as shown inFigs. 1 and 2, where 1 is a central bolt with nut 1 for holding thecovers 1 of the steam-drum 1 in place against the end of the drum, and 2is a similar bolt with nuts 52 for holding the covers 2 of thewatervessel 2 in place against the ends of the said vessel, the heads ofthe bolts and the nuts bearing against the outsides of the said covers.

To separate the steam from the water projected into the steam-drum 1from the upper ends of the bent tubes at and 9, a baffle or baffles isor are provided. A convenient construction of balile for this purpose,according to this invention, shown in Figs. and 4, and consists of anumber of bars or strips 15 arranged parallel with each other and at adistance apart in two or more rows, the bars or strips in one row beingopposite the spaces between the bars or strips in the adjacent row, thearrangement being such that when jets of mixed Water and steam areprojected upon the baffle the water will be arrested and the steamallowed to pass between the bars or strips to the main steampipe 10. Thebars are connected together at their ends by suitable carriers orsupports 17, and are preferably grooved in the direction of theirlength, so as to be of angular, semicircular or equivalent form incross-section. In the example shown they are of angular form and aresupported within the steam-drum between the upper ends of the tubes andthe steam-pipe 16 by plates 18 18, the upper of which may also serve asabaille for the jets of mixed steam and water issuing from the upperends of the tubes 9 and of some of the tubes at.

\Vhat I claim is- 1. A water-tube boiler comprising a watervesselarranged along one side of the firegrate from front to back of theboiler, a steam-drum arranged parallel with and above said water-vessel,a casing containing the same, a longitudinal main group of tubesconnecting said water-vessel and steam-drum and arranged in apractically diagonal manner from one side of the boiler to the other soas to divide the easing into two longitudinal. chambers the lower ofwhich serves as the fire-box of the boiler, and a longitudinal row oftubes connecting the water-vessel and steam-drum and arranged to extendfrom front to back of the boiler and to form the opposite side of thefirebox, substantially as described.

2. A water-tube boiler comprising a casing with uptake, a steam-drum anda water-vessel arranged one above the other at one side of and withinsaid easin g, a longitudinal group of bent tubes connecting saidsteam-drum and water-vessel and arranged to divide the interior of thecasing practically in a diagonal manner, into two longitudinal chambers,the lower of which serves as a fire-box and in the upper of which saidsteam-drum is located, and a blast-pipe passing through the casing andthrough the upper chamber close to the casing and the steam-drum intothe uptakepipe, substantially as described.

3. A water-tube boiler comprising an upper steam-drum, a lowerwater-vessel, a 1011- gitudinal main group of bent tubes connecting theupper side of said steam-drum with said water-vessel, arranged to formone side and the roof of a fire-box, and some of which are arranged toform close sides of a flue in which the remaining tubes are arranged,said flue being in communication with the fire-box and with the uptakeof the boiler, a close wall of tubes connecting said steam-drum andwater-vessel and arranged to form the other side of said fire-box, and acasing with uptake inclosing the said steam -drum water-vessel andtubes, substantially as herein described.

4. In a water-tube boiler, the combination with an upper steam-drum anda lower watervessel, of a longitudinal row of bent tubes connected tosaid steam-drum and water-vessel, said tubes being arranged closetogether along their upwardly-extending portions so as to form a closetubular wall at one side of the fire-box and having their lower portionsbent horizontally or approximately so and made of smaller cross-sectionthan the upper portions so as to form hollow grate-bars with air-spacesbetween, substantially as herein described.

5. The combination with the steam-drum of a water-tube boiler, tubesarranged to direct streams of water and steam into the upper partthereof, and a steam-outlet pipe leading into the steam-drum, of abaffle arranged within said steam-drum between the upper ends of saidtubes and said steam-outlet pipe and comprising a number of connectedbars or strips grooved in the direction of their length and arranged soas to alternate with each other, substantially as herein described forthe purpose specified.

6. A water-tube boiler comprising a casing 3, a steam-drum 1,-awater-vessel 2, a longitudinal group of tubes that extends from front tobackof said boiler, connects said watervessel with the upper side ofsaid steam-drum, is arranged to divide the interior of said casing intoupper and lower longitudinal chambers, and forms one side and the roofof the lower of said chambers which serves as a firebox, downtake-tubes7 arranged in the upper chamber between the vertical side of said casingand said longitudinal group of tubes, and a longitudinal close row oftubes that also connects the water-vessel with the upper side of saiddrum and constitutes the other side of said fire-box, substantially asdescribed.

7. A water-tube boiler comprising a casing 3, steam-drum 1, water-vessel2, inner and outer groups of bent tubes 4 and 9 respect ively connectingsaid Water-vessel with the upper side of said steam-drum and forming thesides and roof of a fire-box, and one or more downtake-tubes 7 arrangedin the space between said casing and the inner group of tubes 4 some ofsaid tubes 4 being arranged to form a flue with lower and upper openings4 and 4, and said tubes 9 being arranged to extend over the tubes 4 andbent to form openings 9 and a damper arranged to control said openings 9substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN ISAAC THORNYOROFT.

Witnesses PERCY E. ll/IATTOCKS, EDMUND S. SNEWIN.

